Bag loading mandrel

ABSTRACT

Bag loading mandrel means for receiving and cuffing a plurality of bags arranged thereon in nested disposition, the mandrel including means for internally and externally gripping the nested bags firmly during the cuffing operation in order to provide accurate and repeatable cuffing. The mandrel is arranged to dimensionally expand those surfaces contacting the bag interior during the cuffing operation, in order to enhance the retention of the bags on the mandrel. Cuffing is accomplished by means of the forward motion of a plurality of cuffing rods normally disposed radially inwardly of the bag surfaces. Forward motion of the rods is initiated while the rods are in contact with the inner wall of the innermost bag in the nested stack at a point adjacent the upper lip, and continued until the upper edge portion of the bag becomes inverted and the cuff accordingly formed.

United States Patent 1191 Adams et a1.

[ Mar. 12, 1974 1 1 BAG LOADING MANDREL [75] inventors: Richard C. Adams, West Barrington; David R. Snowman, Providence; James R. Ambler, Pawtucket; Philip J. Houle, Smithfield, all of R11.

[73] Assignee: G. T. Schjeldahl Company,

Northfield, Minn.

122 Filed: Dec. 17, 1971 52 us. c1. 93/32, 93/8 R, 93/93 HT 51 1m. 01 .1B31b 1/28, B3lb 1/98 [58] Field of Search 1. 93/8 R, 8 WA, 32, 11, 12,

93/93 HT, 84 TW 3,313,216 4/1967 Piazze 1. 93/8 R Primary ExaminerTravis S. McGehee Assistant Examiner-Horace M. Culver [57] ABSTRACT Bag loading mandrel means for receiving and cuffing a plurality of bags arranged thereon in nested disposition, the mandrel including means for internally and externally gripping the nested bags firmly during the cuffing operation in order to provide accurate and repeat'able cuffing. The mandrel is arranged to dimensionally expand those surfaces contacting the bag interior during the cuffing operation, in order to enhance the retention of the bags on the mandrel. Cuffing is accomplished by means of the forward motion ofa plurality of cuffing rods normally disposed radially inwardly of the bag surfaces. Forward motion of the rods is initiated while the rods are in contact with the inner wall of the innermost bag in the nested stack at a point adjacent the upper lip, and continued until the upper edge portion of the bag becomes inverted and the cuff accordingly formed.

8 Claims, 11 Drawing Figures [56] References Cited UNITED STATES PATENTS 3,606,821 9/1971 Tsien 1. 93/8 R 2,961,930 11/1960 Wamsley et a1 .1 93/8 R X 3,513,755 5/1970 Nestler et a1 93/8 WA X 2,893,294 7/1959 Eaton et a1 93/8 WA Q 45 42 5a tli 2 80 74 I 9% 85 as 87 27 47 5 5 2 1?; w -e! l 6: 17 c 56 a I. k 8 I 50 19 51 52 I r w k i 111" p I I 20,]- 54 L 9 1 5 81 Z6 J g 4 91,9- fin:

PATENTEBIIAR 12 m4 SHEU '4 BF 4 f; if? 1 9158 1693 168 14215272511101 f INVENTORS 4 /:$?51%.$521::: 15 BY $2721; 51352 22 3mm I mfg;

BAG LOADING MANDREL BACKGROUND OF THE INVENTION mandrel which is arranged to receive and cuff a plurality of bags fabricated from flexible film materials and disposed in nested relationship upon the mandrel structure. The apparatus is arranged to uniformly form and prepare cuffed portions on the bag structures, with the cuffed portions being arranged adjacent the upper lip edge of the individual bags. This cuff formation makes it possible to remove the innermost bag from the stack at any time, without experiencing unusual difficulty in separation. I

In the dispensing of merchandise in flexible film bags, it has been found desirable to retain the bags in opened disposition for filling, since the film material normally does not have sufficient rigidity to sustain its own weight and be free-standing. Bags having a cuffed lip may be retained in a suitable holding fixture so as to permit loading of the innermost bag in the series, and when loading has been completed, this bag may be removed from the stack with the next adjacent bag then being ready for loading. Such an arrangement is particularly adapted for retain grocery outlets.

The present mandrel apparatus is particularly adapted to receive bag units which are delivered sequentially from a conveyor, particularly a conveyor of the type disclosed and claimed in U. S. Pat. No. 3,595,139, issued July 27, 1971, entitled APPARA- TUS FOR NESTING BAGS, Richard C. Adams, et al., which patent is assigned to the same assignee as the present invention. Bags delivered to the mandrel on such a conveyor are nested upon the mandrel and as such provide the arrangement for ultimately inverting the upper lip portion of the stack, and thereby form the cuffv SUMMARY OF THE INVENTION Briefly, in accordance with the present invention, a bag loading mandrel is provided which is arranged to receive a plurality of bags in nested relationship upon the mandrel, these bags being fabricated from flexible film material. The mandrel is formed so as to present a plurality of bag receiving surfaces, with these bag receiving surfaces being arranged to reciprocatorily move between a retracted disposition which is employed during loading, and an expanded disposition which is employed during the cuffingoperation. The cuffing operation is formed by a family of rod elements which are capable of moving laterally outwardly and into contact with the inner surface of the innermost bag in the stack, and thereafter move forwardly along the axis of the bag structure and thereby insert the upper portion of the bag adjacent the lip. This inversion of course forms the cuff of the bag. When this operation is conducted upon a stacked arrangement of bags, the entire nested stack is cuffed, thereby making it possible to remove the bags from the stack one-at-a-time, with the innermost bag being the one to be removed.

The mandrel structure is provided with a clamping means for externally clamping the bag stack onto or against the mandrel surface. This clamping occurs immediately prior to cuffing and aids in retaining the nested stack in proper disposition on the mandrel.

Also, in order to avoid a. build up of friction between the tips of the cuffing rods and the bag surfaces, means are provided for reducing the friction along the rod tips. It has been found preferable to utilize freely rotating discs or wheels at the tips for making the actual contact with the bag surface.

Following the formation of the cuff on the bag stack, the individual stacks are ejected from the mandrel and removed, the mandrel thereby being prepared for a subsequent loading and cuffing operation.

Therefore, it is a primary object of the present invention to provide an improved bag loading mandrel which is particularly adapted to receive and cuff a plurality of flexible film bags which are loaded onto the mandrel in nested relationship one upon the other.

It is a further object of the present invention to provide an improved apparatus for receiving and cuffing a plurality of nested bags, wherein the mandrel structure is arranged to be expanded across certain of its dimensions while the bags are disposed thereon, this expansion aiding in retention of the bags upon the mandrel structure.

It is yet a further object of the present invention to provide an improved bag receiving mandrel which is adapted to form a cuff adjacent the upper lip portion of the bags, with this cuff being formed by laterally and axially movable cuffing rods.

It is still a further object of the present invention to provide an improved bag receiving mandrel which has means for inverting and cuffing bags loaded thereon, the cuffing means including a family of rods which move outwardly while in contact with the inner surface of the bag stack, the tips of the cuffing rods being arranged to generate little, if any, friction between the rod tipand the bag surface. 7

Other and further objects of the present invention will become apparent to those skilled in the art upon a study of the following specification, appended claims, and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view, partially broken away, of the bag loading mandrel fabricated in accordance with the principles of the present invention;

FIG. la is a fragmentary detail view illustrating the disposition of the expander plates while in retracted disposition, with these plates being shown in expanded disposition in FIG. 1;

FIG. 2 is a top plan view of the structure illustrated in FIG. 1, and showing in addition, a portion of the bag ejecting assembly;

FIGS. 3, 4, 5 and 6 are detail side elevational views of the mandrel structure, with these figures illustrating the disposition of the bag on the mandrel, and further illustrating in progressive steps, the movement of the individual rods during the cuffing operation, with FIG.

3 illustrating the disposition'at the start of the cuffing operation; FIG. 4 illustrating the motion of the rods outwardly at the early stage of the cuffing operation; FIG. 5 illustrating the forward motion of the cuffing rods during the cuffing operatiom-and FIG. 6 illustrating the disposition of the rods at the termination of the cuffing operation;

FIG. 7 is adetail end view taken along the line and in the direction of the arrows 77 of FIG. 1;

FIG. 8 is a perspective view illustrating a pair of bag receiving mandrels, with one .mandrel in a bag receiving or loading mode, while the other is in a bag unloading or discharge mode;

FIG. 9 is a top plan view of the unloading mechanism as it advances toward the lip portion of the nested bag stack; and

FIG. 10 is a perspective view of the control apparatus utilized to sequentially actuate the individual components of the structure during use, and particularly during the sequence of clamping, cuffing, and unloading.

DESCRIPTION OF THE PREFERRED EMBODIMENT THE MANDREL STRUCTURE .In FIG. 1, side plate is shown in plan view, while only a fragmentary portion of side plate 19 is shown.

As is apparent in FIGS. 1 and 2, upper and lower mandrel plates 17 and 18 are cut away in their central or interior portions to form openings such as at 22 in FIG. 2, these openings being occupied by expander plates 23 and 24. These expander plates are illustrated in their expanded disposition in FIG. 1, while FIG. la illustrates the plates in retracted or normal bag-loading disposition. The forward end portions of the upper and lower mandrel plates 17 and 18 are secured together by block member 26, block member 26 having a face plate as at 27 for the purpose of providing a resilient cushion for the bottom wall of the bags, and also for providing a locking surface on the nose of the mandrel for the bottom of a gusseted bagv With attention being continued to be directed to FIGS. 1 and 2, it will be observed that a pair of clamping assemblies generally designated 29 and 30 are provided immediately above and below the upper and lower mandrel plates respectively. These clamping systems are identical in each instance, and thus similar reference numerals will be applied to each. The clamping systems each include a clamping plate or camming plate 31 arranged to make initial contact with the surface of the bags retained on the mandrel along its inwardly facing edge surface. Clamping plates 31 are mounted upon bell crank arm 32, and plate motion upon initial contact is controlled about pivot point 33 by contact wheel 34. Contact wheel 34 is secured by suitable bracket means to crank 32, and is resiliently received on journaled support shaft 35 by means of compression spring 36. Stop nut 37 controls the extent of axial motion of shaft 35 within sleeve 35a. Bell crank 32, as is indicated, is pivotally secured to link 39, link 39 being pivotally connected to support plate 40 by pivot 41, and actuated by cylinder 42, the rod portion 43 of cylinder 42 being coupled to link 39 by pivot pin 44. As is indicated, cylinder 42 is secured to member 40 by means of a clamping bracket or member 45.

The full line view of FIG. 1 illustrates the clamping systems 29 and 30 in bag-gripping disposition. The position assumed by these members during the bagloading operation is in phantom, it being appreciated that the plates 31 will bemoved out of the area during loading.

One particular feature of the clamping systems 29 and 30 is the angle at which camming plate 31 strikes the surface of the bags held on the mandrel. For example, in FIG. 1, bag structures are illustrated as at 47, and these bags are held in place on the mandrel while at rest. As the camming plate 31 approaches the surface of the mandrel, wheel 34 strikes the bag surface, and the edge portion 48 is first to make contact with the bag. The phantom disposition of the clamping systern 29 as illustrated in FIG. 1 illustrates the disposition of wheel 34 during approach to the bag and mandrel surface. Thus, with edge 48 in contact with the outer surface of the bags, the counter-clockwise pivot of plates 31 about pivot point 33 will tend to snug-up the bag stack on the mandrel prior to the cuffing operation described hereinafter.

In order to move the expander plates 23 and 24 between retracted and expanded disposition, cylinders 50 and 50a are provided, each cylinder having a rod such as rod 51, the free end of which is pivotally secured to a plate actuating linkage. The linkage includes a drive link 52 having a pair of arms 5353 pivotally secured thereto as at 54 and 55. Cylinder 50 and its linkage arrangement actuates the upper expander plate 23, while cylinder 50a and its identical associated linkage actuates bottom expander plate 24. In the view of FIG. 1, shaft 56 is journaled within the side plates 19 and 20, and rotate with the links 53-53. A similar rod is shown at 5757 for the lower arms used to actuate plate 24. The links disposed in slaved relationship to the full links 53, and which are disposed on the opposite lateral surface are preferably actuated by shorter link arm members 5858, these links 5858 each deriving motion from shafts 56 and 57 respectively.

It will be noted that the base of cylinder 50 is secured to the upper andlower mandrel plates 17 and 18 by means of mounting bracket 60, this providing a base for forward and rearward reciprocatory motion of member 52 upon extension and retraction of rod 51 from cylinder 50.

With continued attention being directed to FIGS. 1 and 2, the structure of the cuffing mechanism will now be discussed. Essentially, the cuffing system generally designated 65 includes a family of laterally and axially movable cuffing rods 66, 67, 68 and 69. For purposes of locating these rods in the drawings, they are illustrated in FIGS. 1 and 2, and also completely in FIG. 7. The cuffing assembly 65 further includes a backing plate or member which contains and secures the back tip portion of each of the rods 66 69 inclusive, and provides for the forward as well as a portion of the lateral motion. Plate 70 is preferably rectangular in configuration and forms a mounting plate or bracket for each of the rods 66-69 inclusive.

As has been indicated, rods 6669 are utilized to invert the lip portion of the nested bags disposed on the mandrel structure, and in order to accomplish this motion, a variety of articulating mechanisms are utilized. The articulation mechanism includes a first mechanism for moving the cuffing rods laterally, and a second for moving these rods axially. Both motions are required during the cuffing operation. Essentially, the rear end portions of each of the cuffing rods 66, 67, 68 and 69 are anchored to plate 70 and the axial motion is achieved by virtue of motion of plate 70. The lateral motion is obtained by virtue of motion available in expander slides, which will be discussed in detail hereinafter. Mounting plate 71 is utilized for securing certain of the linkage, with plate 71 being stationary. An expander slide guide is provided'for each rod, these expander slide guides being formed in or mounted on arms 72 and 73, for example, for rods 66 and 67 respectively. A guide pair forming a channel is shown at 73a and 7311 on arm 73. These guides serve to limit the axial movement of expander slides 82 and 83 for example. Cylinders 76 and 77 are mounted on bracket 78 and 79 respectively, with these brackets being, in turn, secured to plate'71, as indicated. Each expander slide for the rods 66-69 such as at 82 and 83 is pivotally secured to a link member which is shown, for example,

at 80 in FIG. 1 and at 80 and 81 in FIG. 2. These link members move the expander slides radially outwardly as required. Pivot point 85 is shown as the point attach ing link 80 to expander slide 82.

As is indicated in FIG. 2 of the drawings,- cylinder 76 is provided with rod 87 which is, in turn, coupled to yoke 88. Yoke 88 is, in turn, secured to brackets such as at 89, bracket 89 being coupled to link 80 to actuate and move expander slides 82 and 84 laterally. The normal disposition of the individual cuffing rods is illustrated in FIG. 3, while the radially outwardly expanded disposition of these rods, following outward lateral movement, is illustrated in FIGS. 4, 5 and 6. The disposition of FIG. 1 shows these rods in retracted lateral disposition, but moved forwardly a distance sufficient to underlie the bag lip.

In order to provide for axial motion of the cuffing rods 6669 inclusive, a pair of cylinders are provided, including cylinder 92 and cylinder 93. Cylinder 92 is a cuff rod positioner, and is utilized to move the individual cuffing rods 66-69 forwardly a modest distance so as to assume the position illustrated in FIG. 1. It will be appreciated further that cylinder 93 is the main cuffing cylinder and motion of rod 94 of cylinder 93 functions to move plate 70 forwardly, and thus perform the essentials of the cuffing operation. Cylinder 92 is provided with rod 95 which is also utilized to move plate 70 a modest distance, so as to underlie the bag lips prior to the lateral motion achieved by or through the functioning of cylinders 76 and 77. The base of cylinder 93 is secured to frame 97. Guide sleeve 98 is secured to plate 70, such as by welding or the like, and is adapted to be slidably received over guide shaft 99. As is indicated, guide shaft 99 is secured to plate 71 at one end, and is secured at its opposite end to suitable frame means, such as frame 97.

Cuff rod positioner cylinder 92 is received within a bore in arm 101, this arm being clampingly secured to slide rod 99, arm 101 having a bore formed therein to accommodate rod 99. Upon actuation of cylinder 92 so as to extend rod 95 therefrom, the motion in the system is simply a forward progression of plate 70, with the rear surface 102 of arm 101 resting against a set collar 94a on rod 99. Thus, positioner cylinder 92 merely functions to dispose cuffing' rods 66-69 in their desired.

axial positions prior to lateral expansion of these rods.

In order to avoid friction during the cuffing operation per se, it will be observed that the individual cuffing rods 6'6-69 are provided with a small wheel or disc element such as at 105 in FIG. 3. These disc elements are mounted in the individual rods 6669 by means of the bifurcated tip portions of the individual rod members. Inasmuch as each of these cuffing rods is identical, one to another, it will suffice to say that each rod is provided with such a disc. As an alternative, these rods may be provided with low friction tips, such as by way of a low friction coating of molded polytetrafluoroethylene or the like.

In order to retain the individual bag elements in proper disposition on the mandrel structure, a pair of generally flexible or resilient arms extend along the side plates, such as the arms 108 and 109. These individual arms are provided with a ratchet wheel adjacent the tip end thereof, such as the ratchet wheels 1110 and 111. These ratchet wheels are adapted to move freely in one direction, wheel 110 being arranged to move freely in a counterclockwise direction, while resisting motion in a clockwise direction, and ratchet wheel 1 1 1 is adapted to move freely in a clockwise direction, while resisting motion in a counter-clockwise direction. Thus, as the individual bags move onto the structure from the conveyor, there is resistance to outward motion of the bags at any time. This has been found to be helpful in maintaining the bag stack in desired disposition on the mandrel.

' MANDREL OPERATION A. Bag-Receiving Mode In the bag-receiving mode, the components of the structure will be in the following general configuration:

l. Clamping plates 31 will be retracted to the phantom disposition illustrated in FIG. 1;

2. Expander plates 23 and 24 will be in the disposition shown in FIG. 1a;

3. Cuffing rods 66-69 will be retracted to a point to the rear of that illustrated in FIG. 1 so as to avoid interference with the bag lips.

The structure will be otherwise in the disposition illustrated in FIG. 8, particularly the disposition of mandrel station 112. The conveyor will accordingly be able to deliver individual bags onto the mandrel for ultimate cuffing.

B. Bag-Gripping Mode In order to achieve the bag-gripping mode in the structure, cylinders50 and 50a are actuated so as to move rod and clevis 51 of cylinder 50 (and a corresponding rod and clevis of cylinder 50a) to the left from the disposition illustrated in FIG. la, and into the disposition illustrated in FIG. 1. This motion of the rod and clevis 51 will move toggle links 53-53 into a position so as to move expander plate 23 outwardly from the upper mandrel plate 17. A corresponding action occurs with cylinder 50a and its linkage to actuate plate 18. Following the expander actuation, gripping plates 31-31a move into contact with the outer surface of the outermost bag in the stack. As has been previously indicated, tip end 48 of the plate 31 makes initial contact with the bag and accordingly cams the bag upwardly and snugs the bottom wall of the bag against abutment 27. As is indicated, this motion is achieved by actuation of cylinders 42 and 42a.

Also, during the gripping mode, positioning cylinder 92 is actuated so as to move or position cuffing rods 66-69 forwardly so as to underlie the lip portion of the bags received on the mandrel.

C. Bag-Cuffmg Mode For the bag-cuffing mode to proceed, the individual components of the system are intially in the configuration illustrated in the solid lines in FIG. 1, this following actuation or forward motion of rod 95 from positioner cylinder 92.

The initial articulating motion of the system occurs upon. forward motion of rod 87 of cylinder 76, and rod 77a of cylinder 77. This motion, as previously indicated, expands cuffing rods 66-69 outwardly from the disposition illustrated in FIGS. 2 and 3, through that shown in FIG. 4, and ultimately into the lateral disposition illustrated in FIG. 5. It is normally desirable to momentarily relax the lateral expansion of the cuffing rods prior to the forward motion of the rods, thus permitting the bag stack to more uniformly respond to the forward cuffing motion. This motion is more ully described hereinafter. Upon again achieving full lateral expansion of the cuffing rods 66-69, cylinder 93 is activated so as to move rod 94 forwardly or to the left in FIG. 1, and thus start the cuffing rods on their axial forward direction of travel. This motion is illustrated initially in FIG. 5, and upon completion of the forward motion or stroke, the structure is in the disposition illustrated in' FIG. 6.

As has been indicated, the forward motion of the cuffing rods causes an inversion of the upper lip portion of the nested bags resting on the mandrel to occur, thus providing the ultimate disposition of the bags as illustrated in FIG. 6.

It will be noted that the configuration of the expander plates 23 and 24 is such that clamping plate 31 along with its companion plate 31a form a base for the folding of the cuff. In other words, as the cuff is being formed on the lip portion of the bag, this recess which is shown in expander plates 23 and 24 provides for this accommodation. Therefore, it is possible for plates 31 and 31a to rest within this recessed zone.

BAG UNLOADER Attention is now directed to FIGS. 8 and 9 of the drawings wherein the unloader feature of the structure is illustrated. In this connection, a means is provided for gripping the cuffed lip portion of the bags, and ultimately withdrawing them from the mandrel surface. For example, the unloader mechanism includes a cylinder 115 which is secured to frame mount 116, and which has a rod 117 extending therefrom. A generally U-shaped bracket 118 is provided at the forward end of rod 117, with the base of the U-shaped bracket being secured to the tip of the rod 117. The tip ends of the legs of bracket 1 18 are provided with a gripping finger which is adapted for limited pivotal rotation. Specifically, post number 120 is provided at the free end of bracket 118, with fingers 121 and 122 pivotally mounted thereon. Pivot pins, such as pin 123, is utilized to secure fingers 121 and 122 to the bifurcated support brackets such as the bracket 124. Also, resilient means are provided for permitting clockwise rotation of finger 121 to a limited degree about bracket 124, so as to accommodate positioning of the device in the disposition illustrated in FIG. 8. Accordingly, finger 121 will move in a clockwise direction, while finger 122 will move in a counter-clockwise direction, thus permitting these fingers to grip the upper lip portion of the bags during the extraction stroke.

A. Bag-Unloading Mode In order to unload the cuffed nested bags from the mandrel, cylinder is actuated and rod 117 moves in the direction of arrow until the fingers 121 and 122 are in the position illustrated in FIG. 8, having passed over the lip portion of the bags. Upon reaching this point, the cylinder 115 is actuated in the reverse direction, and since fingers 121 and 122 are not able to move beyond the right angle disposition shown in FIG. 8, the bags are removed from the structure.

PROVISION OF MULTIPLE STATIONS As is indicated in FIG. 8, a pair of stations are provided, one for bag receiving, the other for bag unloading. In order to conserve the operation time, and provide an in-line system, the bags are preferably formed on a bag-making machine, preferably of the bottomseal type, and delivered by a conveyor from the bagmaking machine to the mandrel assembly 10. As has been indicated hereinabove, bottom seal bag making machines are commercially available, and the conveyor mechanism is preferably of the type disclosed and claimed in US. Pat. No. 3,595,139, described hereinabove. In using such an arrangement, the bags are delivered up from the conveyor to the station illustrated at in FIG. 8, and with the conveyor running continuously, the mandrel remains in the position shown at 130 until it has received a full compliment of bags, for example, 20 or 25. Upon achieving this count, the mandrel is moved in the direction to the left in FIG. 8, and is unloaded by means of the unloader assembly generally designated 131. At this time, mandrel 113 will move into the loading position, this being accomplished while mandrel 112 is being unloaded. Upon receiving its full compliment of bags, mandrel 113 will be moved to the right in FIG. 8, and to the disposition actually shown therein.

Therefore, in order to achieve constant motion, a pair of cuffing and unloading stations will be provided with these stations being made alternately available to two mandrels, each mandrel sharing the common loading station, while having its own cuffing and unloading station. Suitable conveyor means, not shown, are provided for removing the individual groups of bags from the unloading station.

As is indicated in FIG. 8, cylinder 133, along with its rod 134, may be utilized to move frame means laterally along shafts 1313, thus achieving the positioning for the mandrels, as required.

CONTROL SYSTEM The control system for operating this system is relatively simple, and consists of a system such as is illustrated in FIG. 10. This system, generally designated includes a motor 141 with a driven shaft 142, carrying a plurality of cams 143153 respectively, each of these cams carrying a cam actuated switch element 154164 inclusive. The individual cam actuated switches are coupled to a suitable source of power, not shown, and carry leads extending to solenoid operated valves l65175 inclusive. Each of these solenoid operated valves is utilized to control the flow of fluid under pressure to actuate the individual cylinders in the system. Preferably a pneumatic system is utilized.

In the arrangement illustrated, motor 141 is coupled to a position sensing control and will initiate its cycle of operation when a mandrel is delivered to the unloading station, as detected by a suitable cam switch mechanism disposed along shafts l3-l3 for each appropriate unloading station. It will be appreciated, of course, that cylinder 133 is controlled by the counter, functioning alternately on each successive count completion event.

With reference to FIG. 10,and upon initiation of the single revolution of motor 141, the following events will occur:

1. Cam switch 154 is closed by cam 143, thus energizing solenoid valve 165. Cylinder 1 is actuated, extending rod 117 until fingers 121 and 122 pass the lip of the bag stack.

2. Cam switch 155 is energized by cam 144, thus energizing solenoid valve 166. Cylinder 50 is actuated to move rod 51 inwardly from the configuration of FIG. la to that of FIG. 1.

3. Cam switch 156 is energized by cam 145, thus energizing solenoid valve 167. Cylinder 92 is actuated by valve 167 to move rod 95 outwardly so as to underlie the bag lips or tops.

4. Cam switch 157 is energized by cam 146, thus energizing solenoid valve 168. Cylinders 76 and 77 move rods 87 and 77a outwardly to move cuffing rods laterally outwardly. As indicated, this motion may have a modified cycle superimposed thereon so as to permit momentary lateral inward motion of the rods, following by a second lateral motion outwardly to full expanded disposition.

Cam switch 158, energized by cam 147, energizes solenoid valve 169. Cylinders 42 and 42a, coupled to valve 169, retract their respective rods to move from the view shown in phantom in FIG. 1 to the full line view of that figure.

6. In a similar manner, valve 170 is energized, thus actuating cylinder 93, moving rod 94 outwardly to form the cuffing operation.

7. Solenoid valve 171 is energized, thus actuating double-acting cylinders 42 and 42a, so as to reverse the operation in step (5) hereinabove.

8. Solenoid valve 172 is energized, thus actuating double-acting cylinder 93, moving rod 94 inwardly on a retracting stroke. This retraction continues sufficiently far so as to coincidentally retract rod 95 of single-acting cylinder 92.

9. Solenoid valve 173 is energized, thus actuating double-acting cylinders 76 and 77, so as to reverse the lateral motion achieved in step (4) herein above. I

I0. Solenoid valve 174 is energized, thus actuating double-acting cylinder 50, the motion being opposite to that described in step (2) hereinabove, and

returning the expander plates to the disposition of cylinders, it is possible to replace certain of these structures with cylinders having a spring-return mechanism employed therewith. In such an instance, the pressure applied to the cylinder during actuation, would be continued until the operation of that particular cylinder is complete, whereupon the spring return would function to complete the return stroke.

As previously indicated, the cuffing rods are initially moved laterally outwardly so as to engage the upper portion of the bags, and this initial expansion is followed by a momentary relaxation and second full expansion prior to forward axial motion of the rods. It has been found that this modified program permits the individual bags in the stack to assume a more uniform or fully relaxed disposition prior to the forward motion of the rods.

In the event the snugging operation is important to the characteristics of the bags, it may be desirable to modify the cycle to a limited extent. In this connection, the mandrel expander plates may be retracted slightly during the snugging of the nested bags on the mandrel. Following the retraction, the expander plates would quickly return to the full open position prior to the commencing of the cuffing operation.

In order to provide for adequate time to accomplish the cuffing operation, it is recommended that the sequence be such that a delay may be encountered in the cuffing operation following the termination of the cuffing operation and the completion of the next loading cycle. Excess time is found to be desirable when pressures available in the systems may drop below prescribed minimums, thus providing some sluggish operation in the system. By providing adequate time, however, such as a timed cycle of 15 seconds to accomplish the cuffing and unloading operation, while the bag loading operation is calculated to require 20 seconds. This additional five seconds will be sufficint to accommodate those normal timing problems which occur in this type of operation.

We claim:

1. Apparatus for receiving and cuffing a plurality of bags fabricated of flexible film material and disposed in nested relationship upon a mandrel structure, each of the bags having a bottom wall, side walls adjoining said bottom wall at one end and terminating in a lip at the top end thereof, said apparatus comprising:

a. a bag loading mandrel body having a plurality of bag receiving surfaces generally defining a rectangular parallelepiped, with said body having bag receiving surfaces arranged to be disposed adjacent said bottom' bag wall andtop bag end, means for reciprocatorily movingopposed portions of said surfaces between a retracted disposition inwardly of said parallelepiped and an expanded disposition outwardly of said parallelepiped, each of said moving opposed surface portions being attached to support arms mounted for rotation about generally parallelly disposed pivot axes located inwardly of said opposed surfaces, means for rotatably moving said support arms about said pivot axes wherein said moving surface portions rock outwardly and upwardly toward that bag receiving surface portion adjacent said top bag end to correspondingly form a bag loading mandrel having a normal retracted bag receiving configuration with certain first crosssectional dimensions and an expanded bag restraining configuration with certain second crosssectional dimensions which exceed said first crosssectional dimensions;

b. rod means disposed laterally adjacent said mandrel and having relatively movable tips, said rod means being normally disposed in contracted disposition with the cylindrical periphery of the rod being retained within the confines of said retracted rectangular parallelepiped, first rod actuating means arranged to move said rods radially outwardly from said contracted disposition to an expanded disposition;

c. second rod actuating means being arranged to move said rods axially from a normal retracted disposition through a forwardly directed bag cuffing path, said second rod actuating means being arranged to move said rods forwardly while in radially expanded disposition.

2. The apparatus as defined in claim 1 being particularly characterized in that the tip ends of said rod means are provided with wheel elements having peripheral. portions extending beyond the outer circumference of the rod tips.

3. The apparatus as defined in claim 1 being particularly characterized in that said second rod actuating means are arranged to reciprocatorily move said rods, said rods being retracted while in said expanded disposition.

4. The apparatus as defined in claim 1 being particularly characterized in that clamping means are provided laterally outwardly of said mandrel, and linkage means are provided to move said clamping means inwardly for releasably clamping the walls of said nested bags against the surface of said mandrel when said second rod actuating means commence forward motion of said rods.

5. The apparatus as defined in claim 4 being particularly characterized in that said clamping means are adapted to make contact with said bag surfaces so as to provide camming motion to the bags so as to urge the bags further onto said mandrel body.

6. The apparatus as defined in claim 1 being particularly characterized in that bag unloading means are provided for removing cuffed bags from said mandrel.

7. In combination with a conveyor having a flight with means sequentially delivering bags to a loading station, mandrel means for receiving and cuffing a plurality of bags fabricated of flexible film material in nexted relationship upon said mandrel structure, said bags having a bottom, and side walls adjoining said bottom at one end and terminating in a lip at the top end thereof,

a. said bag receiving mandrel body defining a rectangular parallelepiped and having a plurality of bag receiving surfaces arranged to be disposed adjacent said bottom bag wall and top bag end, means for reciprocatorily moving opposed portions of said surfaces between a retracted disposition inwardly of said parallelepiped and an expanded disposition outwardly of said'parallelepiped, each of said moving opposed surface portions being attached to support arms mounted for rotation about generally parallelly disposed pivot axes located inwardly of said opposed surfaces, means for rotatably moving said support arms about said pivot axes wherein said moving surface portions rock outwardly and upwardly toward that bag receiving surface portion adjacent said top bag end to correspondingly form a mandrel having a normal retracted bag receiving b. means for movably positioning said mandrel between loading and unloading dispositions, said loading disposition being in the line of said conveyor flight, and said unloading disposition being removed from said line of flight;

d. rod means disposed laterally adjacent said mandrel and having relatively movable tips, said rod means being normally disposed within the confines of said retracted rectangular parallelepiped and having first rod actuating means arranged to move said rods radially between contracted and expanded dispositions; second rod actuating means being arranged to move said rods axially from a normal retracted disposition through a forward bag cuffing path, said second rod actuating means being arranged to move said rods forwardly while in radially expanded disposition.

8. Apparatus for receiving and cuffing a plurality of bags fabricated of flexible film material and disposed in nested relationship upon a mandrel structure, each of the bags having a bottom wall, side walls adjoining said bottom wall at one end and terminating in a lip at the top end thereof, said apparatus comprising:

a. a bag loading mandrel body having a plurality of bag receiving surfaces generally defining a rectangular parallelepiped, with said body having bag receiving surfaces arranged to be disposed adjacent said bottom bag wall and top bag end, said surfaces including upper and lower walls, with said upper and lower walls including a plate with an outer portion and with the central portion being cut away to form an opening therein, an inner plate disposed within said opening and having means for reciprocatorily moving said central portion between a retracted disposition and an expanded disposition, each of said moving opposed surface portions being attached to support arms mounted for rotation about generally parallelly disposed pivot axes located inwardly of said opposed surfaces, means for rotatably moving said support arms about said pivot axes wherein said moving surface portions rock outwardly and upwardly toward the bag receiving surface portion adjacent said top bag end to correspondingly form a bag loading mandrel having a normal retracted bag receiving configuration with said central portion being in retracted disposition and an expanded bag restraining configuration with said central portion being in expanded disposition;

b. rod means disposed laterally adjacent said mandrel and having relatively movable tips, said rod means being normally disposed in contracted disposition with the cylindrical periphery of the rod being retained within the confines of said outer plate portion, first rod actuating means arranged to move said rods radially outwardly from said contracted disposition to an expanded disposition outwardly of said outer plate portion;

0. second rod actuating means being arranged to move said rods axially from a normal retracted disposition through a forwardly directed bag cuffing path, said second rod actuating means being arranged to move said rods forwardly while in radially expanded disposition. 

1. Apparatus for receiving and cuffing a plurality of bags fabricated of flexible film material and disposed in nested relationship upon a mandrel structure, each of the bags having a bottom wall, side walls adjoining said bottom wall at one end and terminating in a lip at the top end thereof, said apparatus comprising: a. a bag loading mandrel body having a plurality of bag receiving surfaces generally defining a rectangular parallelepiped, with said body having bag receiving surfaces arranged to be disposed adjacent said bottom bag wall and top bag end, means for reciprocatorily moving opposed portions of said surfaces between a retracted disposition inwardly of said parallelepiped and an expanded disposition outwardly of said parallelepiped, each of said moving opposed surface portions being attached to support arms mounted for rotation about generally parallelly disposed pivot axes located inwardly of said opposed surfaces, means for rotatably moving said support arms about said pivot axes wherein said moving surface portions rock outwardly and upwardly toward that bag receiving surface portion adjacent said top bag end to correspondingly form a bag loading mandrel having a normal retracted bag receiving configuration with certain first cross-sectional dimensions and an expanded bag restraining configuration with certain second cross-sectional dimensions which exceed said first crosssectional dimensions; b. rod means disposed laterally adjacent said mandrel and having relatively movable tips, said rod means being normally disposed in contracted disposition with the cylindrical periphery of the rod being retained within the confines of said retracted rectangular parallelepiped, first rod actuating means arranged to move said rods radially outwardly from said contracted disposition to an expanded disposition; c. second rod actuating means being arranged to move said rods axially from a normal retracted disposition through a forwardly directed bag cuffing path, said second rod actuating means being arranged to move said rods forwardly while in radially expanded disposition.
 2. The apparatus as defined in claim 1 being particularly characterized in that the tip ends of said rod means are provided with wheel elements having peripheral portions extending beyond the outer circumference of the rod tips.
 3. The apparatus as defined in claim 1 being particularly characterized in that said second rod actuating means are arranged to reciprocatorily move said rods, said rods being retracted while in said expanded disposition.
 4. The apparatus as defined in claim 1 being particularly characterized in that clamping means are provided laterally outwardly of said mandrel, and linkage means are provided to move said clamping means inwardly for releasably clamping the walls of said nested bags against the surface of said mandrel when said second rod actuating means commence forward motion of said rods.
 5. The apparatus as defined in claim 4 being particularly characterized in that said clamping means are adapted to make contact with said bag surfaces so as to provide camming motion to the bags so as to urge the bags further onto said mandrel body.
 6. The apparatus as defined in claim 1 being particularly characterized in that bag unloading means are provided for removing cuffed bags from said mandrel.
 7. In combination with a conveyor having a flight with means sequentially delivering bags to a loading station, mandrel means for receiving and cuffing a plurality of bags fabricated of flexible film material in nexted relationship upon said mandrel structure, said bags having a bottom, and side walls adjoining said bottom at one end and terminating in a lip at the top end thereof, a. said bag receiving mandrel body defining a rectangular parallelepiped and having a plurality of bag receiving surfaces arranged to be disposed adjacent said bottom bag wall and top bag end, means for reciprocatorily moving opposed portions of said surfaces between a retracted disposition inwardly of said parallelepiped and an expanded disposition outwardly of said parallelepiped, each of said moving opposed surface portions being attached to support arms mounted for rotation about generally parallelly disposed pivot axes located inwardly of said opposed surfaces, means for rotatably moving said support arms about said pivot axes wherein said moving surface portions rock outwardly and upwardly toward that bag receiving surface portion adjacent said top bag end to correspondingly form a mandrel having a normal retracted bag receiving configuration with certain first cross-sectional dimensions and an expanded bag restraining configuration with certain second cross-sectional dimensions which exceed said first cross-sectional dimensions; b. means for movably positioning said mandrel between loading and unloading dispositions, said loading disposition being in the line of said conveyor flight, and said unloading disposition being removed from said line of flight; d. rod means disposed laterally adjacent said mandrel and having relatively movable tips, said rod means being normally disposed within the confines of said retracted rectangular parallelepiped and having first rod actuating means arranged to move said rods radially between contracted and expanded dispositions; second rod actuating means being arranged to move said rods axially from a normal retracted disposition through a forward bag cuffing path, said second rod actuating means being arranged to move said rods forwardly while in radially expanded disposition.
 8. Apparatus for receiving and cuffing a plurality of bags fabricated of flexible film material and disposed in nested relationship upon a mandrel structure, each of the bags having a bottom wall, side walls adjoining said bottom wall at one end and terminating in a lip at the top end thereof, said apparatus comprising: a. a bag loading mandrel body having a plurality of bag receiving surfaces generally defining a rectangular parallelepiped, with said body having bag receiving surfaces arranged to be disposed adjacent said bottom bag wall and top bag end, said surfaces including upper and lower walls, with said upper and lower walls including a plate with an outer portion and with the central portion being cut away to form an opening therein, an inner plate disposed within said opening and having means for reciprocatorily moving said central portion between a retracted disposition and an expanded disposition, each of said moving opposed surface portions being attached to support arms mounted for rotation about generally parallelly disposed pivot axes located inwardly of said opposed surfaces, means for rotatably moving said support arms about said pivot axes wherein said moving surface portions rock outwardly and upwardly toward the bag receiving surface portion adjacent said top bag end to correspondingly form a bag loading mandrel having a normal retracted bag receiving configuration with said central portion being in retracted disposition and an expanded bag restraining configuration with said central portion being in expanded disposition; b. rod means disposed laterally adjacent said mandrel and having relatively movable tips, said rod means being normally disposed in contracted disposition with the cylindrical periphery of the rod being retained within the confines of said outer plate portion, first rod actuating means arranged to move said rods radially outwardly from said contracted disposition to an expanded disposition outwardly of said outer plate portion; c. second rod actuating means being arranged to move said rods axially from a normal retracted disposition through a forwardly directed bag cuffing path, said second rod actuating means being arranged to move said rods forwardly while in radially expanded disposition. 